Sample code does not properly verify responseCode

[mintplugins]

The sample code for a credit card transaction does not verify the responseCode properly. Using fraud filters in my sandbox, I have a scenario where my response code is 4, which means the transaction was declined.

But this check allows it to go through as though the transaction was all fine:
https://github.com/AuthorizeNet/sample-code-php/blob/master/PaymentTransactions/charge-credit-card.php#L97

Notice the response code is not being checked there at all.